Core patch stringing method

ABSTRACT

A method for facilitating the manufacture of magnetic core memory arrays. A plurality of miniature toroidal cores are mounted on patches with the apertures therethrough aligned along parallel rows and columns. A plurality of wires equal in number to the number of columns of cores on the patch, and unwound from a supply spool for an extended distance and the leading end is manually threaded through the aligned apertures, such that only a short length of wire extends beyond the last row of cores. These ends are then clamped and a motor driven belt is used to transport the patch along the extended lengths of wires toward the supply spool. When the first patch has been moved by the belt a relatively short distance, another patch of cores can be manually threaded on the same wires and again transported by the motor driven belt and this process repeated until the extended length of wires is filled with core patches.

United States Patent [191 Beck et al. Mar. 25, 1975 CORE PATCH STRINGINGMETHOD Primary Examiner-Carl E. Hall [75] Inventors: Ronald Beck,Bloomington; :iirnrney,Alglentilplrl lizrnzf-Thomas J. Nikolai; KennethDennis L. Breu, Stillwater, both of race ars ruex Minn. [73] Assignee:Sperry Rand Corporation, New [57] ABSTRACT York, NY. A method forfacilitating the manufacture of magnetic core memory arrays. A pluralityof miniature toroidal [221' Ffled' July 1974 cores are mounted onpatches with the apertures [21] Appl. No.: 484,648 therethrough alignedalong parallel rows and columns. Applicatim Dam c oilfil lfi oli if 1E?52m; mfiul flifi [62] g g g Sept 1973 supply spool for an extendeddistance and the leading end is manually threaded through the alignedapertures, such that only a short length of wire extends be- [52] US. Cl29/604, 29/203 MM, 2294244313, yond the last row of cores These ends arethen Int Cl H0 clamped and a motor driven belt is used to transport I go I s l s q I s I s l l l a I l s s I l s l s I s s s e l u e s s s I sl e l n- [58] Field of Search i g i agy g z fig k the supply spool. Whenthe first patch has been moved by the belt a relatively short distance,another patch of 56 R f u d cores can be manually threaded on the samewires and l 1 e erences le again transported by the motor driven beltand this UNITED STATES PATENTS process repeated until the extendedlength of wires is lS(wenson.l 29/604 filled with core patches. rag eta. a

2 Claims, 1 Drawing Figure REGULATED AIR SUPPLY CORE PATCH STRINGINGMETHOD CROSS-REFERENCE TO RELATED APPLICATIONS work station foradditional manufacturing operations.

OBJECTS It is accordingly an object of the present invention to Thisapplication is a division of application Ser. No. 5 provide an improvedmethod for manufacturing mag- 401,469 filed Sept. 27, 1973, entitledCore Patch Stringing Apparatus and now U.S. Pat. No. 3,849,861.

BACKGROUND OF THE INVENTION Toroidal magnetic cores have long been usedin the computer industry as an addressable information storage media.The cores may be arranged in a rectangular array and a plurality ofstrands of fine wire, such as AWG 42 having a diameter of 0.00249inches, are threaded through the core apertures in the array. A typicalarray may comprise 128 rows and 128 columns or a total of 16,384individual cores. Each core may have an outside diameter of 0.023 inchesand an inside diameter of 0.015 inches.

In the past, when manually stringing core arrays, it has been thepractice for the operator to utilize relatively short individual lengthsof pre-cut wire having a threading needle butt welded thereon. Assuch,each typical array might require 256 individual wires, each equippedwith a threading needle.

' We are also aware of various prior art automatic or semiautomatic corestringing machines wherein the array to be threaded is held in a fixedposition and the wires to be threaded are removed from spools andadvanced through the core array, by means of drive rollers. For examplesof these prior art machines, reference is made to the Fielder et al U.S.Pat. No. 3,331,126; the Raickle U.S. Pat. No. 3,587,160 and the Shawetal U.S. Pat. No. 2,958,126. Because of the close tolerancesinvolved, thecomplexity and attendant cost of these machines are relatively high. Themanual method outlined above tends to be slow and is wasteful in termsof material costs in that a needle assembly can be used only once instringing a single array.

The present invention provides a relatively simple, inexpensive,semiautomatic machine for facilitating the manufacture of magnetic corememory arrays in which the threading needles employed can be usedrepeatedly for threading multiple arrays. In carrying out the method ofthis invention an array of cores affixed to a backing sheet (hereinafterreferred to as a core patch) is located at an operators work station. Aplurality of wires, equal in number to the number of columns of coresinthe array and each having a threading needle butt welded to the endthereof, are unwound from a spool located a substantial distance fromthe work station. These wires are maintained in a parallel relationshipwith one another and are positioned over a motor driven conveyor beltwhich extends from the spool location to the work station. An operatormanually guides the needles through the cores on the core patch andslides the patch onto the belt, which thereafter transports the patchalong the wires and away from the work station. When the first patch isout of the way, the operator threads the same wires through additionalpatches, one-by-one, and allows them to be transported by the movingbelt towards the spool location. After the extended length of wires hasbeen filled with core patches, the wires may be severed at predeterminedlocations and the resulting groups of patches, with wires extendingtherethrough, can be removed to another netic core memory arrays.

Yet another object of the invention is to provide an assembly method forstringing magnetic cores wherein the threading needles employed can beused for stringing more than a single array.

The novel features of this invention as well as the invention itself,both as to its organization and method of operation, will best beunderstood from the following description when read in connection withthe accompanying drawing which illustrates by means of a mechanicalschematic the novel apparatus used to carry out the method of thisinvention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Before describing the novelmethod for facilitating the manufacture of magnetic core memory arrays,consideration will first be given to a description of the apparatusemployed in carrying out the method.

As shown in the FIGURE, there is provided a supply reel 10 on which iswound a pluralityof individual strands of fine wire 12 which is to. bethreaded through a corresponding plurality of columns of toroidalmagnetic cores. For example, the reel 10 may contain 128 separatestrands. The leading end of each of the plurality of fine wires 12 has astiffened member 14 (hereinafter termed a threading needle) butt weldedthereto. In the practice of this invention, the threading needle may beapproximately 12 inches long and the wire 12 attached thereto may be inthe range of from four feet to one-hundred feet, although limitation tothis range is not intended and should not be inferred.

In leaving the spool 10, the wires are passed between a pair ofoppositely driven friction rollers 16 and over the upper leg of aconveyor belt 18 which is motor driven in a direction indicated by thesmall arrows 20 and 22. Located directly beneath the upper leg of theconveyor belt 18 is a rubber or flexible plastic sheet of material whichis impregnated with magnetic particles. The magnetic field produced bythe underlying strip 24 passes through the upper leg of the conveyorbelt 18 so as to exert a magnetic attractive influence on the magneticcore patches, thus increasing the frictional force between the corepatches and the top surface of the upper leg of the conveyor belt 18. Alimit switch 26 is located near the endof the conveyor belt 18 andserves to interrupt the power to the conveyor belt drive motor when acore patch has traversed the entire length of the conveyor.

Located at the operators work station at the end of the conveyor belt 18remote from reel 10 is an air bearing plate 28 comprising a chamber 30having as an upper surface 32 a perforated plate through which air canpass. The chamber 30 is connected to a regulated air pressure source(not shown) by means of a flexible plastic tube 34. This fixture servesto float a core patch such as patch 36 in position as the operatorinserts the threading needles 14 through the aligned columns ofapertures in the cores mounted on the patch.

To transfer a core patch from the air bearing plate 28 to the conveyorbelt 18, a second motor driven conveyor belt 42 is provided. This secondbelt is substantially shorter in length than the belt 18 and may have asprocket-to-sprocket distance of only 8 to 10 inches (approx.). Thisshort belt is needed to avoid damage to the insulative coating on thewires and to the magnetic cores which might otherwise occur if the corepatch is tipped or distorted during the transfer operation. The beltdrive motor control circuits are such that upon depression of a startswitch (not shown) the short belt 42 will run for approximately sixseconds whereas the long belt is driven for only about four seconds. Thedifference in operating times insures that a core patch leaving the workstation air bearing plate 28 will be transferred to the long belt andwill be spaced relative to adjac'ent patches as desired.

Also located in proximity to the work station are first and second setsof solenoid operated clamps 38 and 40. A push-button control panel (notshown) is provided which allows the operator to selectively energize theclamps 38'and 40 as well as to control the'conveyor belt drive motorsand the motor driving the tension rollers 16.

Now that the apparatus has been described in detail, consideration willbe given to the details of the method employed for stringing multiplecore patch arrays. The operating sequence is as follows: I

l. The operator unreels the needlewires 12 from the spool 10, threadsthem through a set of tension rollers 16, routes them over the conveyorbelts l8 and 42 and secures them under the two sets of solenoid operatedclamps 38 and 40. The machine is now set up for operation.

2. A first core patch is positioned on the air bearing plate 28, clamp38 is released (opened) and the core patch 36 is positioned onto theneedles 14 and is slid between the open jaws of the clamp 38 to aposition between clamp 38 and the closed clamp 40 and rests on the shortconveyor belt 42. Another core patch is mounted on the needles 14 butthis second patch temporarily remains to the right of the clamp 38.Clamp 38 is then again energized and closed.

3. The operator presses another control button which causes the solenoidclamp 40 to open and the conveyor belt drive motors and the drive motorfor the tension rollers 16 to be energized. The control circuit for theconveyor belt drive motors is such that both motors are energizedsimultaneously, but the motor for the short conveyor belt 42 is allowedto run approximately two seconds longer than the drive motor for thelong conveyor belt 18. Thus, the core patch located on the short drivebelt will pass between the now open clamp 40 and onto the long conveyorbelt 18 without being tipped or twisted. The motor driving the frictionrollers 16 is energized and de-energized in synchronism with the drivemotor for the short conveyor belt 42 such that whenever the patches arebeing moved by the short conveyor belt 42, tension will be maintained onthe plural electrical conductors threading through the multiple corearrays.

4. Clamps 38 and 40 are again energized to clamp the wires and steps 2through 4 above are repeated until the wires overlaying the longconveyor belt 18 are filled with the desired number of core patches.

5. The individual patches are then grouped as desired and the wires aremaintained in'alignment by adhesive tape or other suitable means andthen a group of patches and wire segments threading through them are cutout and transferred to another work station for further stringingoperations dictated by the design of the magnetic core array.

Thus it can be seen that there has been shown and described a novelmethod for facilitating the construction of magnetic core memory arrays.It is to be understood, however, that various changes, modifications andsubstitutions in the form and details of the described method can bemade by those skilled in the art without departing from the scope of theinvention as defined by the following claims.

What is claimed is:

1. A method for stringing magnetic core arrays comprising the steps of:

a. locating a core patch having a plurality of toroidal shaped coresmounted thereon, on edge, with the apertures of said cores aligned alonga plurality of rows and columns at a work station;

b. manually threading a first end of each of a plurality of wiresindividually through the apertures of a respective one of said columns;

0. clamping said first end of said plurality of wires to maintain themin a taut condition; and

d. sliding said core patch away from said work station along saidplurality of wires for an extended, predetermined distance.

2. The method as in claim 1 and further including the steps of:

a. repeating steps a), b) and c) while step d) is in progress.

1. A method for stringing magnetic core arrays comprising the steps of:a. locating a core patch having a plurality of toroidal shaped coresmounted thereon, on edge, with the apertures of said cores aligned alonga plurality of rows and columns at a work station; b. manually threadinga first end of each of a plurality of wires individually through theapertures of a respective one of said columns; c. clamping said firstend of said plurality of wires to maintain them in a taut condition; andd. sliding said core patch away from said work station along saidplurality of wires for an extended, predetermined distance.
 2. Themethod as in claim 1 and further including the steps of: a. repeatingsteps a), b) and c) while step d) is in progress.